English verb conjugation
COULD INSTALL

Regular verb: install - installed - installed

Affirmation

Simple form	V-ing form
I could install you could install he could install we could install you could install they could install	I could be installing you could be installing he could be installing we could be installing you could be installing they could be installing
Perfect	V-ing perfect
I could have installed you could have installed he could have installed we could have installed you could have installed they could have installed	I could have been installing you could have been installing he could have been installing we could have been installing you could have been installing they could have been installing

Negation

Simple form	V-ing form
I could not install you could not install he could not install we could not install you could not install they could not install	I could not be installing you could not be installing he could not be installing we could not be installing you could not be installing they could not be installing
Perfect	V-ing perfect
I could not have installed you could not have installed he could not have installed we could not have installed you could not have installed they could not have installed	I could not have been installing you could not have been installing he could not have been installing we could not have been installing you could not have been installing they could not have been installing

Interrogative form

Simple form	V-ing form
could I install? could you install? could he install? could we install? could you install? could they install?	could I be installing? could you be installing? could he be installing? could we be installing? could you be installing? could they be installing?
Perfect	V-ing perfect
could I have installed? could you have installed? could he have installed? could we have installed? could you have installed? could they have installed?	could I have been installing? could you have been installing? could he have been installing? could we have been installing? could you have been installing? could they have been installing?

Interro-negative form

Simple form	V-ing form
could I not install? could you not install? could he not install? could we not install? could you not install? could they not install?	could I not be installing? could you not be installing? could he not be installing? could we not be installing? could you not be installing? could they not be installing?
Perfect	V-ing perfect
could I not have installed? could you not have installed? could he not have installed? could we not have installed? could you not have installed? could they not have installed?	could I not have been installing? could you not have been installing? could he not have been installing? could we not have been installing? could you not have been installing? could they not have been installing?